Acronym in the sports world for "Did Not Finish". Ironically, however, the #1 Vaporware of all time, "Duke Nukem Forever" (known also as "Duke Nukem Taking Forever", ".. If Ever", ".. Whenever") coincidentally has the exact same acronym.

A project (usually a video game) that has taken so long to complete that one of two possibilities exist: either the project will never be completed, or in the even that the project is completed, it will be so crappy that it would've been better off never being completed. The term is derived from Duke Nukem Forever, the most famous example of this.

I want Beyond Good and Evil 2 released just as much as the next red-blooded gamer, but at this point, I'm pretty sure it's a DNF.